Reducing valve for steam Yoshitake GDK-2000

Direct acting valve of simple design. The best choice for pressure control in branch lines and in front of small equipment.

1. In a direct acting valve, there are fewer active parts, the design is simple but strong.
2. Spherical main valve provides good sealing and reduced valve seat leakage (ANSI Class IV).
3. Large sized diaphragm for high Cv and ability to control load changes.
4. Easy pressure adjustment thanks to remote control; wide range of pressure settings.

*  NPT connection options available.

* The above values in brackets are JIS 10K FF flange dimensions and weights.

* Contact us for other specifications.

GDK-2000 Specification Selection Chart

See Refer to the selection chart above to select the most suitable pressure reducing valve option. Find the point of intersection between the inlet pressure (P1) and the reduced pressure (P2). If the crossover point is within range (A), the pressure reduction should be carried out in two steps. If within the range (B) - the control range. If within range (C), maximum performance cannot be achieved. When depressurizing in two stages, the distance between the valves must be at least 3 m.

Sizing Chart for GP-2000 Series (Steam, External Impulse Tube)

Example.
When sizing a pressure reducing valve at inlet pressure (P1), reduced pressure (P2) and flow rate of 0.6 MPa, 0.4 MPa and 600 kg/h, respectively, first find the intersection point (a) of the pressure lines at the inlet 0.6 MPa and reduced pressure 0.4 MPa. From this point, draw a line downward until it intersects with the line corresponding to a flow rate of 600 kg/h — intersection point (b). Since the point of intersection (b) lies between the dimensions 20A and 25A, it is necessary to choose the larger of the two — 25A.
*The margin factor should be taken equal to 80-90%.

Flow curve

When selecting a nominal size, set the flow rate to 80-90% of the design flow so that the pressure loss and temperature loss of the shut-off valve, filter, etc., before or after the pressure reducing valve can be used. In order for the pressure reducing valve to exhibit maximum flow characteristics, do not select a small diameter pipeline as a countermeasure against the influence of resistance in the pipe. Select a nominal size based on the nominal size selection chart.

GDK-2000 pressure curve

This graph shows the underpressure change when the 1.4MPa valve inlet pressure starts to fluctuate between 0.2MPa and 1.4MPa, while the underpressure pressure is set at 0.14 MPa.

GDK-2000 Pneumatic Load Pressure Setting Table

How to read a table (GDK-2000)
If the nominal size — 25A, inlet pressure (P1) — 1.0 MPa, and reduced pressure (P2) — 0.2 MPa, the pneumatic load pressure is calculated as follows: draw a line upwards from the differential pressure point (Delta;P) before and after the pressure reducing valve (1.0 MPa — 0.2 MPa = 0.8 MPa) to find point of intersection (a) with nominal size 25A. Calculate ΔPa (pneumatic load pressure (Pa) - set pressure (P2)) = 0.037 MPa by drawing a horizontal line to the left of the intersection point (a). Thus, the pneumatic load pressure is: (Pa) = .Delta;Pa + P2 = 0.037 + 0.2 = 0.237 MPa.